1. Field of the Invention
The present invention relates to the data structure of map data used by a mobile member, such as a car navigation system, a portable telephone or a portable data-terminal, or by a fixed computer terminal, a map data updating method, a map data storage medium and a map data processing apparatus.
2. Description of the Related Art
For the conventional map data used by a mobile member, such as a navigation system, a portable telephone or a portable data terminal, or a fixed computer terminal, a road system is represented by using nodes to show points along roads, links showing roads between the points and link rows in which a series of roads are shown as connected links, and information concerning the nodes and the links included in the link rows is included in link row data that represent the link rows. The connections between the links in the road system are represented by using identical node information that is included in the link row data and that identifies the nodes between the link rows (refer to JP-A-8-292716 and “Road Data Frame, Kiwi Format Ver. 1.10, Chapter 7.2” published by Kiwi Discussion Committee).
To describe a conventional map data traffic rule for links established between nodes, links approaching nodes and links exiting nodes are separately designated by using a node {travel order in accordance with identical node information} (refer to “Road Data Frame, Kiwi Format Ver. 1.10, Chapter 7.2”).
To correlate links between hierarchical road systems and links between hierarchical road systems and those that are organized for other purposes, such as for route calculation, unique nationwide link numbers for conventional map data are provided for the individual links constituting the road systems at the lowest levels, so that within the link rows, the link numbers are sequential. Further, link numbers within a predetermined range are provided for the links so that even when links are divided, the continuity of the link numbers is maintained by providing link numbers from among those within the predetermined range (refer to “Road Data Frame, Kiwi Format Ver. 1.10, Chapter 7.2” and JP-A-2002-175593).
In addition, for the conventional map data, nodes are correlated with route guide data used as route guides at intersections, and information designating storage locations for the route guide data is provided for the nodes in link rows (refer to “Road Data Frame, Kiwi Format Ver. 1.10, Chapter 7.2”).